For 20 crushing minutes, Mark Kelly thought that his wife Gabrielle Giffords had died.
On board a friend's private plane rushing him and his family to his wife's side, Kelly watched television reports erroneously declare that Giffords had lost her life in the shooting in a Safeway parking lot in Tucson, Ariz., on Saturday, Jan. 8.
"The kids ... Claudia and Claire start crying. My mother, you know ... I think she almost screamed. And I just, you know, walked into the bathroom, and you know, broke down," Kelly, an astronaut, told ABC's Diane Sawyer in an exclusive interview. "To hear that she died is just, it's devastating for me."
For Kelly, it was the worst moment in a nightmarish day. Calling from the plane, Kelly learned the truth from people who were with Giffords at the hospital -- that his wife had not died, but she was fighting for her life.
"It was a terrible mistake," Kelly said about turning on the television. "As bad as it was that she had died, it's equally exciting that she hadn't."
Watch Diane Sawyer's exclusive interview with Mark Kelly on a special edition of "20/20," "The Congresswoman and the Astronaut: An American Story of Love and Strength," at 10 p.m. ET.
In a remarkably personal interview, Kelly revealed that his wife had spoken about 10 times before the shooting of her fears of being shot during one of her town meetings, and Kelly isn't sure she should continue being a member of Congress after her recovery.
Kelly also talks of his wife's remarkable progress and his hope that she'll eventually make a complete recovery.
Kelly, who has been photographed beside his wife's bed holding her hand, said there is a habit of hers that has convinced him that she recognizes him.
"If I hold her hand, she'll play with my wedding ring. She'll move it up and down my finger. She'll take it off ... she'll put it on her own finger. She'll move it to her thumb. And then she can put it back on my finger," he said.
"The reason why I know that that means she recognizes me is because she's done that before. She'll do that if we're sitting in a restaurant. She'll do the same exact movements," he said.
Kelly was struck by Giffords' progress again when "she stuck her hand up on the side of my face" and began giving him a neck massage.
"She spent 10 minutes rubbing my neck and I keep telling her, 'Gabby, you're in the ICU. You know, you don't need to be doing this,'" he said with a chuckle.
Kelly added, "I'm pretty sure she wouldn't do that to somebody else. And she's looking me in the eye."
Nevertheless, he is still unsure about the extent of her eventual recovery.
"At times I'm 100 percent confident that she's going to make a 100 percent recovery," he told Sawyer. "And, you know, at other times I don't know."
Later Kelly said, "She's got a great sense of humor. I've thought about whether that part of her will be the same."
Today's emotions and even laughs are a world away from what was going through his mind a little more than a week ago when Kelly was in Houston and got a phone call from one of his wife's staffers telling him his "Gabby" had been shot. He had spoken to his wife just 30 minutes before.